He said he can't figure out the sense of Yahoo CEO Marissa Mayer's strategy.

He noted that Yahoo seems to be doing two things.

In media, it's investing in big media stars like Katie Couric, David Pogue, and Bobbi Brown. It's investing in longform video content to compete with comedies and drama from HBO and Netflix.

Then, on the other side of the spectrum, Yahoo is building consumer tech products. It's trying to build the next app that everyone will use instead of Gmail, Instagram, or Snapchat.

Peretti told me he thinks this strategy is a big mistake.

He said that Mayer, perhaps because she grew up at Google, seems to be taking on the competition where it is strongest.

"I'm not saying that Yahoo is doomed or anything," Peretti wrote me in a follow-up email today. "I just think it is a strategic mistake to take on big media where they are strongest (stars, scripted shows, etc) and take on big tech where they are strongest (email, mobile tech, social networks, search, etc), especially when there is a huge open space at the intersection of media and tech where it hard for other big cos to compete."